Proceedings of the 2nd Workshop on Adaptive Hypertext and Hypermedia
HYPERTEXT'98, Pittsburgh, USA, June 20-24, 1998

Position Statement: Adaptive navigation tools for thesaurus-based retrieval in cultural heritage applications

Douglas Tudhope
Editor: The New Review of Hypermedia and Multimedia
Computer Studies Department
University of Glamorgan
Pontypridd, Wales, UK
tel 01443-482271
fax 01443-482715

Research on intelligent hypermedia systems has been carried out at the University of Glamorgan (UG) for about five years. Research has investigated how semantic structure underlying information can be used to enhance browsing and search tools via computed links. There have been several publications in the hypermedia, information retrieval and cultural heritage areas. Tudhope has recently (1997) taken up the editorship of the refereed annual review journal New Review of Hypermedia and Multimedia (previously Hypermedia - one of the oldest specialist hypermedia journals). Cultural heritage and adaptive hypermedia are the two special themes for the 1998 issue, and evaluation the special theme for 1997.

Six years ago the University was commissioned to build a hypermedia museum exhibit on local history from the photographic archives of the Pontypridd Historical and Cultural Centre. This inspired a University research assistantship in collaboration with PHCC that resulted in Carl Taylor's PhD work on semantic modelling and navigation in museum hypermedia systems. As part of this work, a number of research prototypes were built investigating a hypermedia architecture with a semantic index space separate from the document space (Beynon-Davies et al 1994, Taylor et al 1994). A variety of conventional hypermedia navigation techniques were implemented with this architecture (Tudhope et al 1994). Primary access routes were time, space and as subject index the Social History and Industrial Classification (SHIC). Rather than using fixed embedded links, navigation was based on queries over an underlying semantic index space, with results post-processed for expression in a particular navigation tool. Queries to the database can be simple or complex. Conventional hypermedia navigation techniques, including both local and global browsers, guided tours, and Boolean queries can be implemented by relatively simple underlying queries. More complex queries return partial matches using measures of semantic closeness between terms in a semantic index space; advanced navigation options included query expansion when a query fails to return results and navigation via similarity to current item (Cunliffe, Taylor, Tudhope 1997). Most existing commercial museum access systems using thesauri rely on interactive approaches or limited query expansion techniques. A classification system, or thesaurus, embodies a semantic network of relationships between terms, the three main thesaurus relationships being hierarchical, associative and equivalence. Thus there is some inherent notion of distance between terms, their 'semantic closeness'. Distance measurements can be exploited to provide more advanced navigation tools. A distance measurement between terms (and between sets of terms) offers the opportunity for imprecise information requests. Semantic term expansion lies at the heart of the measures of closeness between terms in automated term expansion and similarity measures in retrieval tools.

The intention in future research is to build on the principles underlying the semantic index space, extending the semantic model to a full set of thesaurus relationships, and investigate the potential of intelligent navigation tools in a major museum which can facilitate evaluation current collaborators include the Science Museum, London. One issue is tailoring the navigation tool to dynamically adapt to different classes of user. This can affect the visualisation of the thesaurus structure for browsing and the parameters controlling the semantic closeness algorithms and query expansion.

Relevant publications

Beynon-Davies P., Tudhope D., Taylor C., Jones C. 1994. A Semantic Database Approach to Knowledge-based Hypermedia Systems, Information and Software Technology, 36(6), 323-329.

Cunliffe D., Taylor C., Tudhope D. 1997. Query-based navigation in semantically indexed hypermedia. Proceedings 8th ACM Conference on Hypertext (Hypertext'97), Southampton. April, pp 87-95.

Jones C., Taylor C., Tudhope D., Beynon-Davies P. 1996. Conceptual, Spatial and Temporal Referencing of Multimedia objects. Advances in GIS Research II, Proceedings 7th International Symposium on Spatial Data Handling, (eds. Kraak and Molenaar) , August, Delf, pp 2.13-2.26.

Taylor C., Tudhope D., & Beynon-Davies P. 1994. Representation and Manipulation of Conceptual, Temporal and Geographical Knowledge in a Museum Hypermedia System. Proc. ACM European Conference on Hypermedia Technology (ECHT'94), Edinburgh, 239-244.

Tudhope D., Beynon-Davies P., Taylor C., Jones C. 1994. Virtual Architecture based on a Binary Relational Model: A Museum Hypermedia Application, Hypermedia, 6(3), 174-192.

Tudhope D., Taylor C., Beynon-Davies P. 1995. Taxonomic Distance: Classification and Navigation. Proceedings 3rd International Conference on Hypermedia and Interactivity in Museums: Multimedia Computing and Museums (ed. D. Bearman), San Diego, October, pp 322-334.

Jones C., Beynon-Davies P., Taylor C., Tudhope D. 1995. GIS, hypermedia, and historical information access. Proceedings 7th International Conference of the Museum Documentation Association, Edinburgh, Nov, pp 109-113.

Tudhope D., Taylor C. 1996. Flexible Access to Multimedia Museum Collections. Proceedings Electronic Imaging and the Visual Arts (EVA'96), London, July, pp 7.1- 7.11

Tudhope D., Taylor C. 1996. A unified similarity coefficient for navigating through multi-dimensional information. Proc. 59th Conference of the American Society for Information Science (ASIS'96), 67-70.

Tudhope D., Taylor C. 1997. Navigation via Similarity: automatic linking based on semantic closeness. Information Processing and Management, 33(2), 233-242.